Mechanical stoker.



F. M. CLARK.

MECHANICAL STOKER.

APPLICATION FILED NOV. 7, 1911.

1,1 20,445, Patented Dec. 8, 1914.

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MECHANICAL STOKER.

APPLICATION FILED NOV. 7, 1911.

1,1 20,445. Patented Dec. 8, 1914.

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UNITED STATES PATENT ()FFICE;

FRANCIS MORTON CLARK, 0F GARDEN CITY, NEW YORK, ASSIGNOR TO MULTIPLE-GRATE-BAR ENDLESS CHAIN STOKER COMPANY, A CORPORATION OF NEW YORK.

MECHANICAL STOKER.

To all whom it may concern Be it known that I, FRANCIS MORTON CLARK, acitizen of the United States, residing at Garden City, in the county ofNassau and State of New York, have invented a certain new and usefulImprovement in Mechanical Stokers, of which the following is a full,clear, and exact description.

My invention is an improvement in mechanical stokers of the endlesstraveling grate type and relates more particularly to the means forsupporting the traveling grate.

The object of my invention is to provide a structure by which the framemay, in a large measure, be relieved of the weight of the grate, thuspermitting of the frame and shafting being of light material and alsodoing away with the danger of collapse of the heated frame when thestoker is used under large boilers, where the weight of the grate isvery great. To accomplish this re sult I provide a structure whichcarries the weight of a large portion of both the upper and lower runsof the grate to the floor independently of the frame.

In the drawings, Figure 1 is a vertical section of the rear of a furnacetaken on the line :r-w Fig. 2 and looking in the direction of the arrow;Fig. 2 is a partial section on the line y-g Fig. 1, only a portion ofthe grate being indicated and the view broken away at the right for lackof space; Fig. 3 is a perspective of the U-shaped socket bearing inwhich the idler and roller shafts are journaled; and Fig. 4 is adiagrammatic view of a modified form of my invention.

As shown in Fig.1 5 indicates a boiler and 6 an endless traveling gratelocated in the furnace below said boiler. The grate is composed of gratebars 7 mounted on chains 8 running over sprockets 9 carried on shafts 1Ojournaled in the ends of a frame of horizontal members 11, 12 joined byvertical members 13. At the rear of the furnace is the usual retardingplate 14: and ash chamber 15 of which only the front wall 16 is shown inthe drawings.

The structure as so far described is the customary one. The weight ofthe grate requires that it be supported at various points between thesprocket wheels-the upper run by grooved idlers 17 and the lower run byrollers 18. It has been the practice to Specification of Letters Patent.

Application filed November 7, 1911.

Patented Dec. 8, 1914.

Serial No. 658,940.

mount the grooved idlers l7 and the rollers 18 on shafts journaled andsupported on the frame, but according to my invention, the weighttransmitted to the idlers 17 and the rollers 18 is partially or whollysupported independently of the frame. The idlers 17, mounted on shafts19, are of a diameter equal to the distance between the upper and lowerruns of the grate, and roll upon the lower run of the grate. The rollers18 have bushings 20 set in their ends and these bushings carry shortshafts 21. The shafts 19 and 21 are journaled in U-shaped bearings 22secured to the standards 13. These bearings 22 are so located on thestandards that the shafts 19 and 21 normally are at or near the bottomsof the U, which arrangement permits of vertical movement of the shaftsbut prevents horizontal displacement thereof.

The. rollers 18 are shown as resting in roller-bearings 23, 23 carriedin standards 24. I have illustrated two such standards for each rollerand prefer to employ that number, but it is obvious that one or morethan two may be substituted for the number shown without in any waydeparting from my invention.

In the preferred adjustment of this device the shafts 19 and 21 would,if without any load, be supported by the bearings 22. The load of thegrate however will, the shafts being comparatively light, tend todistort the shafts and, as the idlers 17 and the rollers 18 both receivesupport from below, this tendency to distortion is counteracted and thegreater portion of the load 1' transmitted through the standards 24 toth\ floor independently of the frame.

On account of irregularities in thickness of the grate it may frequentlyhappen that the shaft 19 will not be home in the lower part of thebearing 22 and so no load at all will be transmitted through the shaft19 to the frame.

I may, if I desire, so locate the bearings 22 that no load will betransmitted to the frame at any time by the shafts 19, or by either theshafts 19 or the shafts 21, the weight of the upper run of the gratethus being transmitted through the idlers 17 to the lower run of thegrate and the combined weight of the upper and lower runs beingtransmitted through the rollers 18 to the standards 24.

In F ig. 4 I have illustrated a modified form of my invention in which,instead of a number of standards 24: located at different points in thefurnace from front to rear, I provide a single standard 25 extendingfrom front to rear and carrying the several sets of roller bearings 23,23.

Having thus described my invention, what I claim is:

1. In a mechanical stoker, the combination with an endless travelinggrate, of front and rear sprockets over which said grate travels, anidler intermediate said sprockets "supported in whole or in part on thelower run of said grate and supporting the upper run thereof, a shaftupon which said idler is mounted, bearings guiding said shaft butpermitting of vertical movement thereof, a roller below and supportingthe lower run of said grate, bearings guiding said roller but permittingvertical movement thereof, a standard, and roller bearings interposedbetween said standard and said roller.

2. In a mechanicalstoker, the combination with an endless travelinggrate, of front and rear sprockets over which said grate travels, meansintermediate said sprockets supported in whole or in part upon the lowerrun of said grate and supporting the upper run of said grate.

3. In a mechanical stoker, the combination with an endless travelinggrate, of front and rear sprockets over which said grate travels, anidler supported in whole or in part upon the lower run of said grate andsupporting the upper run of said grate,

said idler being free to move vertically.

4. In a mechanical stoker, a frame, sprockets mounted at the front andrear of said frame, an endless grate mounted to travel over saidsprockets, means intermediate said sprockets supported in whole or inpart on the lower run of said' grate and supporting the upper run ofsaid grate, and means, independent of the frame, for supporting thelower run of said grate.

5. In a mechanical stoker, the combination with an endless travelinggrate, of front and rear sprockets over which said grate travels, anidler intermediate said sprockets interposed and extending between theupper and lower runs of said grate, said idler being supported in wholeor in part on the lower run of the grate and so mounted as to be free tomove vertically, a roller supporting the lower run of said grate andmeans independent of the frame for supporting said roller. v

In testimony whereof, I hereunto affix my signature in the presence oftwo witnesses.

FRANCIS MORTON CLARK.

Witnesses v HARVEY ISEMAN, JOHN RADETZKY.

Copies of this patent may be obtained for five cents each, by addressingthe f Commissioner of Patents. Washington, D. C.

